In the early middle ages it was Pengwern, thought to be either modern day Shrewsbury or Bascchurch. During Norman times it was Abergwyngregyn overlooking the Menai Straits.In the late middle ages Owain Glyndŵr made his capital at Machynlleth where he held the first Welsh parliament. Cardiff only became the capital of Wales in 1955.
Cardiff has always been regarded as the Welsh capital over the past few Centuries, although it was only officially designated so by the Welsh Minister in '55.

In Mediaeval times, Strata Florida was the capital, as it was the seat of Welsh King Llewellyn the Great from 1238 in the old Cistercian Abbey there.

During the Glyndwr Rebellion. Machynlleth was effective capital as Glyndwr had his Parliament there from 1404-10.

St. Davids in Pembrokeshire is the ecclesiastical capital of Wales (like Canterbury is in England) as it is the birthplace of St. David, wales's patron saint.

From 1473 to 1689, the English border town of Ludlow was the seat of The Council of Wales and the Marches.
Garth Celyn at Aber Garth Celyn, now known as Abergwyngregyn, Aber, in Gwynedd, north Wales
there wasnt an official capital althogh in the middle ages it was machynlleth and a thousand yrs before that it was pengwern (in powys)
Cardiff became the capital city of Wales in 1955.

The former Welsh capital cities, Deganwy and Aberffraw had been slighted or demolished to prevent them from falling into the hands of English invaders during the twelfth century. From about 1170 until 1955 Wales had no capital.

This only became a problem when Queen Elizabeth II announced her intention of visiting all the UK's capitals after her coronation in 1953, when it was noticed that Wales didn't have a capital.

A competition was held.